Delaying Iron Therapy until 28 Days after Antimalarial Treatment Is Associated with Greater Iron Incorporation and Equivalent Hematologic Recovery after 56 Days in Children: A Randomized Controlled Trial

Use of point-of-care haemoglobin tests to diagnose childhood anaemia in low- and middle-income countries: A systematic review

OBJECTIVES

Anaemia is a major cause of mortality and transfusion in children in low- and middle-income countries (LMICs); however, current diagnostics are slow, costly and frequently unavailable. Point-of-care haemoglobin tests (POC(Hb)Ts) could improve patient outcomes and use of resources by providing rapid and affordable results. We systematically reviewed the literature to investigate what, where and how POC(Hb)Ts are being used by health facilities in LMICs to diagnose childhood anaemia, and to explore challenges to their use.

METHODS

We searched a total of nine databases and trial registries up to 10 June 2022 using the concepts: anaemia, POC(Hb)T, LMIC and clinical setting. Adults ≥21 years and literature published >15 years ago were excluded. A single reviewer conducted screening, data extraction and quality assessment (of diagnostic studies) using QUADAS-2. Outcomes including POC(Hb)T used, location, setting, challenges and diagnostic accuracy were synthesised.

RESULTS

Of 626 records screened, 41 studies were included. Evidence is available on the use of 15 POC(Hb)Ts in hospitals (n = 28, 68%), health centres (n = 9, 22%) and clinics/units (n = 10, 24%) across 16 LMICs. HemoCue (HemoCue AB, Ängelholm, Sweden) was the most used test (n = 31, 76%). Key challenges reported were overestimation of haemoglobin concentration, clinically unacceptable limits of agreement, errors/difficulty in sampling, environmental factors, cost, inter-observer variability and supply of consumables. Five POC(Hb)Ts (33%) could not detect haemoglobin levels below 4.5 g/dL. Diagnostic accuracy varied, with sensitivity and specificity to detect anaemia ranging from 24.2% to 92.2% and 70% to 96.7%, respectively.

CONCLUSIONS

POC(Hb)Ts have been successfully utilised in health facilities in LMICs to diagnose childhood anaemia. However, limited evidence is available, and challenges exist that must be addressed before wider implementation. Further research is required to confirm accuracy, clinical benefits and cost-effectiveness.

Approaches to Address the Anemia Challenge

Anemia is a multifactorial condition; approaches to address it must recognize that the causal factors represent an ecology consisting of internal (biology, genetics, and health) and external (social/behavioral/demographic and physical) environments. In this paper, we present an approach for selecting interventions, followed by a description of key issues related to the multiple available interventions for prevention and reduction of anemia. We address interventions for anemia using the following 2 main categories: 1) those that address nutrients alone, and, 2) those that address nonnutritional causes of anemia. The emphasis will be on interventions of public health relevance, but we also consider the clinical context. We also focus on interventions at different stages of the life course, with a particular focus on women of reproductive age and preschool-age children, and present evidence on various factors to consider when selecting an intervention-inflammation, genetic mutations, nutrient delivery, bioavailability, and safety. Each section on an intervention domain concludes with a brief discussion of key research areas.

Iron supplementation in anemic Zanzibari toddlers is associated with greater loss in erythrocyte iron isotope enrichment

BACKGROUND

Heavy parasitic loads increase the risk of iron (Fe) deficiency anemia, which remains prevalent globally. Where parasites are common, understanding the influence of parasitic infections on Fe incorporation and erythropoiesis in toddlers is especially important.

OBJECTIVES

The aim of this study was to identify the impacts of malarial and helminth infections on red blood cell (RBC) Fe incorporation and subsequent changes in RBC Fe isotope enrichment for 84 days postdosing in toddlers at high risk for parasitic infections.

METHODS

Fe incorporation was measured in a group of Zanzibari toddlers (n = 71; 16-25 months) using a stable Fe isotopic method. At study entry, an oral stable Fe isotope was administered. Blood was collected 14 (D14) and 84 (D84) days postdosing for the assessment of Fe status indicators and RBC isotopic enrichment. Blood and stool samples were collected and screened for malaria and helminth parasites. Factors associated with changes in RBC Fe isotope enrichment were identified using regression models.

RESULTS

Toddlers who had larger weight-for-age z-scores, lower total body Fe, and helminth infections (n = 26) exhibited higher RBC Fe incorporation. RBC Fe isotope enrichment decreased from D14 to D84 by -2.75 percentage points (P < 0.0001; n = 66). Greater loss in RBC Fe isotope enrichment from D14 to D84 was observed in those who received Fe supplementation, those with either helminths or both malarial and helminth infections, and in those with greater RBC Fe incorporation on D14.

CONCLUSIONS

Toddlers who received Fe supplementation exhibited significantly greater losses of RBC Fe isotope enrichment over time. We speculate this greater loss of RBC Fe enrichment is indicative of increased erythropoiesis due to the provision of Fe among anemic or helminth-infected toddlers.

Delayed iron does not alter cognition or behavior among children with severe malaria and iron deficiency

BACKGROUND

Malaria and iron deficiency (ID) in childhood are both associated with cognitive and behavioral dysfunction. The current standard of care for children with malaria and ID is concurrent antimalarial and iron therapy. Delaying iron therapy until inflammation subsides could increase iron absorption but also impair cognition.

METHODS

In this study, Ugandan children 18 months to 5 years old with cerebral malaria (CM, n = 79), severe malarial anemia (SMA, n = 77), or community children (CC, n = 83) were enrolled and tested for ID. Children with ID were randomized to immediate vs. 28-day delayed iron therapy. Cognitive and neurobehavioral outcomes were assessed at baseline and 6 and 12 months (primary endpoint) after enrollment.

RESULTS

All children with CM or SMA and 35 CC had ID (zinc protoporphyrin concentration ≥80 μmol/mol heme). No significant differences were seen at 12-month follow-up in overall cognitive ability, attention, associative memory, or behavioral outcomes between immediate and delayed iron treatment (mean difference (standard error of mean) ranged from -0.2 (0.39) to 0.98 (0.5), all P ≥ 0.06).

CONCLUSIONS

Children with CM or SMA and ID who received immediate vs. delayed iron therapy had similar cognitive and neurobehavioral outcomes at 12-month follow-up.

IMPACT

The optimal time to provide iron therapy in children with severe malaria is not known. The present study shows that delay of iron treatment to 28 days after the malaria episode, does not lead to worse cognitive or behavioral outcomes at 12-month follow-up. The study contributes new data to the ongoing discussion of how best to treat ID in children with severe malaria.

Delayed iron improves iron status without altering malaria risk in severe malarial anemia

BACKGROUND

WHO guidelines recommend concurrent iron and antimalarial treatment in children with malaria and iron deficiency, but iron may not be well absorbed or utilized during a malaria episode.

OBJECTIVES

We aimed to determine whether starting iron 28 d after antimalarial treatment in children with severe malaria and iron deficiency would improve iron status and lower malaria risk.

METHODS

We conducted a randomized clinical trial on the effect of immediate compared with delayed iron treatment in Ugandan children 18 mo-5 y of age with 2 forms of severe malaria: cerebral malaria (CM; n = 79) or severe malarial anemia (SMA; n = 77). Asymptomatic community children (CC; n = 83) were enrolled as a comparison group. Children with iron deficiency, defined as zinc protoporphyrin (ZPP) ≥ 80 µmol/mol heme, were randomly assigned to receive a 3-mo course of daily oral ferrous sulfate (2 mg · kg-1 · d-1) either concurrently with antimalarial treatment (immediate arm) or 28 d after receiving antimalarial treatment (delayed arm). Children were followed for 12 mo.

RESULTS

All children with CM or SMA, and 35 (42.2%) CC, were iron-deficient and were randomly assigned to immediate or delayed iron treatment. Immediate compared with delayed iron had no effect in any of the 3 study groups on the primary study outcomes (hemoglobin concentration and prevalence of ZPP ≥ 80 µmol/mol heme at 6 mo, malaria incidence over 12 mo). However, after 12 mo, children with SMA in the delayed compared with the immediate arm had a lower prevalence of iron deficiency defined by ZPP (29.4% compared with 65.6%, P = 0.006), a lower mean concentration of soluble transferrin receptor (6.1 compared with 7.8 mg/L, P = 0.03), and showed a trend toward fewer episodes of severe malaria (incidence rate ratio: 0.39; 95% CI: 0.14, 1.12).

CONCLUSIONS

In children with SMA, delayed iron treatment did not increase hemoglobin concentration, but did improve long-term iron status over 12 mo without affecting malaria incidence.This trial was registered at clinicaltrials.gov as NCT01093989.

Update of pre- and postnatal iron supplementation in malaria endemic settings

This review focuses on pre- and post-natal iron supplementation in malaria endemic settings. Although iron supplementation can reduce iron deficiency, malaria infection may counteract this effect by the increase of hepcidin, and iron supplementation may further worsen malaria infection by providing additional iron for the parasites. However, most iron supplementation intervention studies in pregnant women with malaria have not shown a negative impact, although malaria treatment with iron supplementation may be beneficial in terms of improving birth outcomes. In infants and young children in malaria endemic settings, the adverse effects of iron supplementation has been well documented and malaria prevention and treatment with iron supplementation is recommended. Besides fostering the growth of malaria parasites, iron may also promote potential pathogens in the gut and cause an inflammatory response in young children. Overall, iron supplementation is beneficial for treating iron deficiency, but needs to be considered in the context of malaria prevention and treatment in pregnant women, infants and young children for safety and effectiveness.

The Benefits and Risks of Iron Supplementation in Pregnancy and Childhood

Iron deficiency is the most common micronutrient deficiency in the world and disproportionately affects pregnant women and young children. Iron deficiency has negative effects on pregnancy outcomes in women and on immune function and neurodevelopment in children. Iron supplementation programs have been successful in reducing this health burden. However, iron supplementation of iron-sufficient individuals is likely not necessary and may carry health risks for iron-sufficient and potentially some iron-deficient populations. This review considers the physiology of iron as a nutrient and how this physiology informs decision-making about weighing the benefits and risks of iron supplementation in iron-deficient, iron-sufficient, and iron-overloaded pregnant women and children.

Drug use in the management of uncomplicated malaria in public health facilities in the Democratic Republic of the Congo

Background

Malaria the first causes of death from parasitic infection worldwide. Interventions to reduce the burden of malaria have produced a tremendous drop in malaria morbidity and mortality. However, progress is slower in DRC, which shares with Nigeria 39% of deaths related to malaria globally. Inappropriate use of drugs may be one of the factors of this below-average performance. The aim of this study was to describe the use of drugs in the management of uncomplicated malaria in public health facilities in DRC.

Methods

A drug use study was carried out in DRC from January to March 2014. In each of the former 11 provinces of DRC, one Rural Health Centre, one Urban Health Centre and one General Hospital were selected. In each of them, 100 patient’s files containing prescription of anti-malarials from January to December 2013 were randomly selected. Among them, all of the files with diagnosis of uncomplicated malaria were included in this study. Prescribed anti-malarials, co-prescribed drugs and their indications were collected. Descriptive analyses were performed.

Results

A total of 2300 files out of 3300 (69.7%) concerned uncomplicated malaria and were included in analysis. Malaria treatment was initiated after a positive RDT or microscopy in 51.5% of cases, upon suspicion without requesting biological confirmation in 37% and despite negative results in 11%. Twenty-nine (29) different treatment regimens were used. The drugs recommended by the National Malaria Control Programme were used in 54.3% of cases (artesunate–amodiaquine 37.4% or artemether–lumefantrine 16.9%). The second most used anti-malarial was quinine (32.4%). Apart from anti-malarials, an average of 3.1 drugs per patient were prescribed, among which antibiotics (67.9%), analgesics and non-steroidal anti-inflammatory (NSAIDs) (all abbreviations to be explicated on first use) (70.6%), vitamins (29.1%), anaemia drugs, including blood transfusion (9.1%) and corticosteroids (5.7%), In 51.4% of cases there was no indication for the concomitant medication.

Conclusion

Management of uncomplicated malaria in DRC is characterized by a low adherence to treatment policy, numerous treatment regimens, and abundant concomitant medication potentially harmful to the patient. This may contribute to the low performance of DRC in malaria control. Determinant of this irrational use of drugs need to be assessed in order to formulate and implement efficient corrective measures.

Novel Schiff base (DBDDP) selective detection of Fe (III): Dispersed in aqueous solution and encapsulated in silica cross-linked micellar nanoparticles in living cell

This work demonstrated the synthesis of (4E)-4-(4-(diphenylamino)benzylideneamino)-1,2-dihydro-1,5- dimethyl-2-phenylpyrazol-3-one (DBDDP) for Fe (III) detection in aqueous media and in the core of silica cross-linked micellar nanoparticles in living cells. The free DBDDP performed fluorescence enhancement due to Fe (III)-promoted hydrolysis in a mixed aqueous solution, while the DBDDP-doped silica cross-linked micellar nanoparticles (DBDDP-SCMNPs) performed an electron-transfer based fluorescence quenching of Fe (III) in living cells. The quenching fluorescence of DBDDP-SCMNPs and the concentration of Fe (III) exhibited a linear correlation, which was in accordance with the Stern-Volmer equation. Moreover, DBDDP-SCMNPs showed a low limit of detection (LOD) of 0.1 ppm and an excellent selectivity against other metal ions. Due to the good solubility and biocompatibility, DBDDP-SCMNPs could be applied as fluorescence quenching nanosensors in living cells.

Approaches for Reducing the Risk of Early-Life Iron Deficiency-Induced Brain Dysfunction in Children

Iron deficiency is the most common micronutrient deficiency in the world. Women of reproductive age and young children are particularly vulnerable. Iron deficiency in late prenatal and early postnatal periods can lead to long-term neurobehavioral deficits, despite iron treatment. This may occur because screening and treatment of iron deficiency in children is currently focused on detection of anemia and not neurodevelopment. Anemia is the end-stage state of iron deficiency. The brain becomes iron deficient before the onset of anemia due to prioritization of the available iron to the red blood cells (RBCs) over other organs. Brain iron deficiency, independent of anemia, is responsible for the adverse neurological effects. Early diagnosis and treatment of impending brain dysfunction in the pre-anemic stage is necessary to prevent neurological deficits. The currently available hematological indices are not sensitive biomarkers of brain iron deficiency and dysfunction. Studies in non-human primate models suggest that serum proteomic and metabolomic analyses may be superior for this purpose. Maternal iron supplementation, delayed clamping or milking of the umbilical cord, and early iron supplementation improve the iron status of at-risk infants. Whether these strategies prevent iron deficiency-induced brain dysfunction has yet to be determined. The potential for oxidant stress, altered gastrointestinal microbiome and other adverse effects associated with iron supplementation cautions against indiscriminate iron supplementation of children in malaria-endemic regions and iron-sufficient populations.

Neurological effects of iron supplementation in infancy: finding the balance between health and harm in iron-replete infants

Iron mediates many biochemical processes in neural networks that proliferate during brain development. Insufficient iron causes irreversible neurodevelopmental deficits, and most high-income countries recommend that infants older than 4-6 months receive additional iron via food fortification or supplementation to prevent iron-deficiency anaemia. Now that the prevalence of iron-deficiency anaemia in children has decreased to less than 10% in most developed countries, concerns that the recommended intakes far exceed those required to prevent iron-deficiency anaemia have been raised, and emerging evidence suggests that iron overexposure could be linked to adverse outcomes later in life. In this Viewpoint, we discuss the importance of iron for neurodevelopment, investigate the biochemical markers used to assess iron stores, summarise the disparity in public health policies among high-income countries, and discuss the potential association between iron overexposure and adverse neurological outcomes later in life. We present a case for new studies to establish the optimal amount of iron that both prevents deficiency and reduces the potential risk of long-term negative health outcomes.

Delaying the start of iron until 28 days after antimalarial treatment is associated with lower incidence of subsequent illness in children with malaria and iron deficiency

We evaluated the incidence of all-cause and malaria-specific clinic visits during follow-up of a recent trial of iron therapy. In the main trial, Ugandan children 6–59 months with smear-confirmed malaria and iron deficiency [zinc protoporphyrin (ZPP > = 80 μmol/mol heme)] were treated for malaria and randomized to start a 27-day course of oral iron concurrently with (immediate group) or 28 days after (delayed group) antimalarial treatment. All children were followed for the same 56-day period starting at the time of antimalarial treatment (Day 0) and underwent passive and active surveillance for malaria and other morbidity for the entire follow-up period. All ill children were examined and treated by the study physician. In this secondary analysis of morbidity data from the main trial, we report that although the incidence of malaria-specific visits did not differ between the groups, children in the immediate group had a higher incidence rate ratio of all-cause sick-child visits to the clinic during the follow-up period (Incidence Rate Ratio (IRR) immediate/delayed = 1.76; 95%CI: 1.05–3.03, p = 0.033). Although these findings need to be tested in a larger trial powered for malaria-specific morbidity, these preliminary results suggest that delaying iron by 28 days in children with coexisting malaria and iron deficiency is associated with a reduced risk of subsequent all-cause illness.

Prediction of human iron bioavailability using rapid c-ELISAs for human plasma hepcidin

BACKGROUND

Hepcidin is the central systemic regulator of iron metabolism, but its quantification in biological fluids is challenging. Rapid, accurate and user-friendly methods are needed. Our aim was to assess the ability of hepcidin as measured by three different c-ELISA assays to predict iron bioavailability in humans.

METHODS

The three assays used were commercially available DRG and Peninsula assays and the c-ELISA method performed at Radboud University Medical Centre, Nijmegen, The Netherlands (Hepcidinanalysis.com), validated by comparative measurements with time-of-flight mass spectrometry. We analyzed plasma samples (n=37) selected to represent a broad range of hepcidin concentrations from a subgroup of healthy, iron-depleted women in a study assessing fractional absorption from iron supplements.

RESULTS

In single regressions, all three c-ELISA assays were predictors of fractional iron absorption: R2=0.363 (DRG), R2=0.281 (Peninsula) and R2=0.327 (Hepcidinanalysis.com). In multiple regressions, models including hepcidin measured with either DRG-, Peninsula or Hepcidinanalysis.com explained 55.7%, 44.5% and 52.5% of variance in fractional absorption, and hepcidin was a strong predictor of fractional absorption irrespective of the hepcidin assays used. However, we found significant differences in absolute values for hepcidin between different methods. Both the DRG assay's (y=0.61x+0.87; R2=0.873) and the Peninsula assay's measurements (y=1.88x+0.62; R2=0.770) were correlated with Hepcidinanalysis.com.

CONCLUSIONS

The biological variability in plasma hepcidin, (inter-sample CV) was 5-10-fold higher for both the Peninsula and DRG assay than the analytical variably (inter-run within-sample CV) suggesting substantial discriminatory power to distinguish biological hepcidin variation. Between methods, prediction of iron bioavailability in generally healthy iron depleted subjects appears comparable.